It is possible to use bash commands in Jupyter Notebook, even on Windows systems, as long as Jupyter is launched from a bash-compliant command line such as Git Bash (MingW64). As shown in the OP's code example, the bash command must be prepended by an exclamation mark (!).
The real key, however, is launching from Git Bash or possibly Ubuntu on Windows .
I'm running windows 10 Pro with Python installed via Anaconda, and the following code works when I launch Jupyter via Git Bash, but does not when I launch from the Anaconda prompt.
>>> !ls
database.sqlite
Weather Data Clustering using k-Means.ipynb
>>>!pip show lxml | grep Version
Version: 4.1.0
{PATH}isn't really a valid Bash expression. Perhaps you mean${PATH}(where however the braces aren't really useful or necessary)? (Not too familiar with Jupyter though.)